KZ is one of those companies, like FiiO before it, that really pushes the performance envelope of budget audiophile gear. Take the KZ ZSA in-ear headphone, this two-way design runs an 8mm dynamic driver for bass, and a balanced armature driver for the treble, both housed in a snazzy CNC machined-aluminum earpiece. The headphones' impedance is rated at 18 ohms, and I like that the braided cable with a one-button mic is user-replaceable. The sound is stunning, and best of all is the ZSA's rock-bottom budget price: $26 on Amazon in the US, £26 on Amazon UK, and AU$28 on Amazon Australia. If I didn't know what they cost I'd guess $100 -- the ZSA is a steal!
The cables are designed to run up and over your ears, I found the ZSA comfy, and noise isolation on the New York subway is average for this type of headphone. As for the sound: wow, it sounds full, with good detail on the new Anna Von Hausswolff album Dead Magic. Her church organ's ultradeep bass notes practically massaged my ear drums! It's not just a lot of bass; the bass definition is rock solid. Hausswolff's vocals were brilliantly clear and clean. And with Yo La Tengo's There's a Riot Going On, the sound is loaded with texture and atmosphere, and the ZSA put me there!
So the ZSA is perfect? Not quite -- it's a bright headphone, so treble detail is somewhat overemphasized. Depending on the recording the ZSA either sounds very clear or too bright. I managed to tame the brightness by experimenting with other brands' ear tips.
I also spent time with the KZ's ZS10 in-ears, which run $58 on Amazon in the US, £59 in the UK, and AU$66 in Australia. First the good news: it's a more-refined and clearer-sounding headphone, no issues with brightness on this one. The ZS10 sports five drivers in each earpiece (one dynamic, four balanced armatures), and impedance is rated at 32 ohms, but the ZS10 didn't fit nearly as well in my ears as the ZSA. Worse yet, the ZS10's silicone ear tips stuck in my ear canals when I took the headphones off, which happened a few times. I'm pretty sure I know why -- the ZS10's ear nozzles where the tips attach are too smooth, so the nozzles don't provide enough grip on the tips. That's a deal-breaker for me, as I don't enjoy retrieving tips stuck in my ears! All in all, the ZS10's poor fit and nozzle design make it impossible to recommend.
Which brings us back to the KZ ZSA. It's got a lot going for it, with a really impressive build and sound quality for a mere $26!